Molecular and Biological Characterization of Lettuce mosaic virus (LMV) Isolates Reveals a Distinct and Widespread Type of Resistance-Breaking Isolate: LMV-Most.
ABSTRACT Lettuce mosaic virus (LMV) causes an economically important seedborne and aphid-transmitted disease of lettuce and ornamental crops worldwide. The genetic diversity among 73 LMV isolates was examined based on a 216-nucleotide sequence at the variable region encoding the NIb-coat protein junction. Three clusters of LMV isolates were distinguished: LMV-Yar, LMV-Greek, and LMV-RoW. In the latter cluster, two subgroups of isolates, LMV-Common and LMV-Most, accounted for a large proportion of the LMV isolates analyzed. These two subgroups included the seedborne isolates, consistent with this property contributing a selective advantage and resulting in widespread distribution. In addition to being seedborne, LMV-Most isolates overcome the two resistance genes commonly used in lettuce, mo1(1) and mo1(2), and thus represent a potential threat to lettuce cultivation. The complete sequence of an LMV-Most isolate (LMV-AF199) was determined, allowing a better definition of the genetic relationships among LMV-Most, LMV-Common, and an additional isolate of the LMV-RoW cluster.
Krause-Sakate
Renate
R
Le Gall
Olivier
O
Fakhfakh
Hatem
H
Peypelut
Martine
M
Marrakchi
Mohammed
M
Varveri
Christina
C
Pavan
Marcelo A
MA
Souche
Sylvie
S
Lot
Hervé
H
Zerbini
F Murilo
FM
Candresse
Thierry
T